1. Field of the Invention
The present invention relates to a pump. In particular, the present invention relates to a pump which is preferably allowed to have a miniature and thin size.
2. Description of the Related Art
Recently, a microminiature pump has been suggested, in which the viscosity of a liquid is thermally changed so that the change in viscosity is utilized in place of a valve.
The microminiature pump has no mechanical valve, and hence there is no fear of abrasion and malfunction. It is approved that such a microminiature pump can be applied to a device to be embedded in the body to administer a trace amount of medicament and to a small-sized chemical analyzer.
It is considered that such a microminiature pump will be extensively applied in the future, for example, to those concerning the medical and chemical analysis fields. In such application, it is of course important that the pump has a miniature and thin size. Further, it is desirable that the pump has a large discharge amount (movement amount) of fluid although it has the miniature and thin size.
Those made of silicon are known as such a microminiature pump. However, in the case of such a pump, the rigidity of the vibrating section is small, and it is difficult to realize a high speed pumping operation and an increase in discharge amount (movement amount) of fluid.
The present invention has been made taking such a problem into consideration, an object of which is to provide a pump which has a miniature and thin size and which makes it possible to increase the discharge amount (movement amount) of fluid.
Another object of the present invention is to provide a pump which makes it possible to efficiently perform pressure reduction on the introducing side and pressure application on the discharge side.
The above and other objects, features, and advantages of the present invention will become more apparent from the following description when taken in conjunction with the accompanying drawings in which a preferred embodiment of the present invention is shown by way of illustrative example.
FIG. 1 shows a sectional view illustrating a pump according to a first embodiment;
FIG. 2 shows a plan view illustrating a main pump body with a casing being removed, concerning the pump according to the first embodiment;
FIG. 3 shows a sectional view illustrating a state in which the depth of a hollow space is decreased in the pump according to the first embodiment;
FIG. 4 shows a sectional view illustrating a portion including a support pillar, concerning the pump according to the first embodiment;
FIG. 5 shows an example of the planar configuration of a pair of electrodes formed on an actuator section;
FIG. 6A illustrates an example of comb teeth of the pair of electrodes arranged along the major axis of a shape-retaining layer;
FIG. 6B illustrates another example;
FIG. 7A illustrates an example of comb teeth of the pair of electrodes arranged along the minor axis of the shape-retaining layer;
FIG. 7B illustrates another example;
FIG. 8 shows a sectional view illustrating an example in which the shape-retaining layer is provided with a pair of electrodes and an intermediate layer;
FIG. 9 shows a sectional view illustrating an example in which an introducing hole and a discharge hole are formed just over an input valve section and an output valve section respectively, concerning the pump according to the first embodiment;
FIG. 10 shows a plan view of the main pump body depicted with the casing being removed, in the example in which the introducing hole and the discharge hole are formed just over the input valve section and the output valve section respectively;
FIG. 11 illustrates a state in which the input valve section and a pump section are driven, concerning the pump according to the first embodiment;
FIGS. 12A to 12F illustrate the operation of the pump according to the first embodiment;
FIG. 13 illustrates an example in which the input valve section and the pump section are driven to form flow passages at the input valve section and the pump section;
FIG. 14 illustrates an example in which the pump section and the output valve section are driven to form flow passages at the pump section and the output valve section;
FIG. 15 shows a sectional view illustrating an example in which a gap is formed between an end surface of a displacement-transmitting section and a back surface of the casing in the pump according to the first embodiment;
FIG. 16 shows a cross-sectional arrangement illustrating a pump according to a first modified embodiment concerning the first embodiment;
FIG. 17 illustrates a state in which the pump according to the first modified embodiment concerning the first embodiment is operated;
FIG. 18 shows a cross-sectional arrangement illustrating a pump according to a second modified embodiment concerning the first embodiment;
FIG. 19 shows a cross-sectional arrangement illustrating a pump according to a third modified embodiment concerning the first embodiment;
FIG. 20 shows a cross-sectional arrangement illustrating a pump according to a fourth modified embodiment concerning the first embodiment;
FIG. 21 shows a cross-sectional arrangement illustrating a pump according to a fifth modified embodiment concerning the first embodiment;
FIG. 22 shows a cross-sectional arrangement illustrating a pump according to a sixth modified embodiment concerning the first embodiment;
FIG. 23 shows a cross-sectional arrangement illustrating a pump according to a seventh modified embodiment concerning the first embodiment;
FIG. 24 shows a cross-sectional arrangement illustrating a pump according to an eighth embodiment concerning the first embodiment;
FIG. 25 shows a sectional view illustrating a pump according to a second embodiment;
FIG. 26 shows a sectional view illustrating another exemplary pump according to the second embodiment;
FIG. 27 shows a sectional view illustrating a pump according to a first modified embodiment concerning the second embodiment;
FIG. 28 shows a plan view illustrating a main pump body with a casing being removed, concerning the first modified embodiment of the pump according to the second embodiment;
FIG. 29 shows a plan view illustrating a main pump body with a casing being removed, concerning a second modified embodiment of the pump according to the second embodiment;
FIG. 30 shows a sectional view illustrating a pump according to a third embodiment;
FIG. 31 shows a model illustrating the pump according to the third embodiment;
FIG. 32 shows a driving sequence for the pump according to the third embodiment;
FIG. 33 shows a model illustrating a first modified embodiment of the pump according to the third embodiment;
FIG. 34 shows a model illustrating a second modified embodiment of the pump according to the third embodiment;
FIG. 35 shows a model illustrating a third modified embodiment of the pump according to the third embodiment;
FIGS. 36A to 36C show models illustrating fourth modified embodiments of the pump according to the third embodiment;
FIG. 37 shows a sectional view illustrating a fifth modified embodiment of the pump according to the third embodiment;
FIG. 38 shows a model illustrating the pressure-reducing operation effected by a fifth modified embodiment of the pump according to the third embodiment;
FIG. 39 shows a model illustrating the pressure-applying operation effected by the fifth modified embodiment of the pump according to the third embodiment;
FIG. 40A shows a sectional view illustrating a sixth modified embodiment of the pump according to the third embodiment;
FIG. 40B shows a sectional view illustrating a situation in which a first pump section is operated in the sixth modified embodiment of the pump according to the third embodiment;
FIG. 41 shows a plan view illustrating a main pump body with a casing being removed, concerning a seventh modified embodiment of the pump according to the third embodiment;
FIG. 42A shows a sectional view illustrating a pump according to a fourth embodiment;
FIG. 42B shows a sectional view illustrating a situation in which a pump section is operated in the pump according to the fourth embodiment;
FIG. 43 shows a sectional view illustrating a pump according to a fifth embodiment;
FIG. 44 shows a sectional view illustrating a modified embodiment of the pump according to the fifth embodiment;
FIG. 45 shows a sectional view illustrating a pump according to a sixth embodiment;
FIG. 46 shows a sectional view illustrating a pump according to a seventh embodiment; and
FIGS. 47A to 47D illustrate the operation of the pump according to the seventh embodiment.